An antibacterial, low-VOC polypropylene composition, its preparation method and application

Abstract

This invention discloses an antibacterial, low-VOC polypropylene composition, its preparation method, and its application, belonging to the field of polymer materials technology. The antibacterial, low-VOC polypropylene composition comprises the following components in parts by weight: 59-86 parts polypropylene resin, 5-20 parts toughening agent, 10-25 parts filler, and 0.5-5 parts functional additive. The functional additive includes glycyl alanine-modified molecular sieve, which is coated with chitosan quaternary ammonium salt. This invention uses a chitosan quaternary ammonium salt and glycyl alanine-modified molecular sieve as a functional additive, and introduces this functional additive into the polypropylene composition. This improves the antibacterial properties of the polypropylene composition, gives it low VOC release performance, and makes it suitable for manufacturing automotive interior parts.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to an antibacterial, low-VOC polypropylene composition, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) resin, as a widely used thermoplastic resin, has been extensively applied in many fields such as automobiles, electronics, and home furnishings due to its advantages such as low density, low cost, convenient molding and processing, and good chemical stability. For example, in the automotive industry, polypropylene materials are commonly used to manufacture interior and exterior parts such as dashboards, door panels, and bumpers; in the electronics industry, polypropylene materials are often used to produce various housings, connectors, and other electronic components; and in the home furnishing industry, it is also often used to make various plastic containers and furniture parts. However, with the increasing demands for health, environmental protection, and user experience in automotive interiors, the shortcomings of polypropylene materials in terms of antibacterial properties and volatile organic compound (VOC) control have gradually become apparent. In terms of antibacterial properties, ordinary polypropylene materials do not have antibacterial capabilities. When automotive interiors are in a warm and humid environment for a long time, bacteria, mold, and other microorganisms can easily grow, which not only produces odors and affects the air quality inside the car, but may also pose potential threats to human health, such as causing allergies and respiratory infections. Regarding VOC emissions, polypropylene materials release volatile organic compounds such as formaldehyde, acetaldehyde, and benzene during processing and use. These substances can cause irritating odors inside the car, and some VOC components are also toxic. Long-term exposure can harm human health and seriously affect the user experience and environmental performance of car interiors.

[0003] Currently, there are many studies on the modification of polypropylene, but there are still shortcomings in the technical solutions that simultaneously achieve excellent antibacterial properties and low VOC release performance. For example, CN120365652A improves the antibacterial properties of polypropylene by adding metal ion antibacterial agents. However, metal ion antibacterial agents often have poor compatibility with the polypropylene matrix, easily leading to agglomeration and uneven antibacterial effect. Moreover, adding large amounts of metal ion antibacterial agents may also affect the mechanical properties and aging properties of polypropylene. In addition, this method does not have a significant effect on reducing VOC release. CN115198526A uses surface coating with antibacterial coating to enhance the antibacterial properties of polypropylene. However, this surface treatment process is complex and costly, and the coating is prone to wear and peeling during use, making it difficult to maintain the antibacterial effect for a long time. At the same time, it cannot solve the problem of VOC release from polypropylene itself.

[0004] Therefore, how to improve the antibacterial properties of polypropylene compositions while reducing their VOC emissions is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] Based on the deficiencies of existing technologies, the purpose of this invention is to provide an antibacterial low-VOC polypropylene composition, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an antibacterial, low-VOC polypropylene composition comprising the following components in parts by weight: 59-86 parts of polypropylene resin, 5-20 parts of toughening agent, 10-25 parts of filler, and 0.5-5 parts of functional additive; The functional additive includes glycyl alanine-modified molecular sieve, which is coated with chitosan quaternary ammonium salt. The mass ratio of chitosan quaternary ammonium salt, glycyl alanine and molecular sieve in the functional additive is (3~12):(5~20):10.

[0007] The inventors discovered that by utilizing the film-forming properties of quaternary ammonium chitosan, functional additives can form a core-shell structure. This core-shell structure uses glycyl alanine-modified molecular sieves as the core and quaternary ammonium chitosan as the coating layer. This allows the functional additives in the polypropylene composition to retain more amino active sites, ensuring the continuous adsorption and reactivity of VOCs during long-term use. By adjusting the mass ratio of quaternary ammonium chitosan, glycyl alanine, and molecular sieve to a suitable range, this invention can effectively protect amino active sites and enhance antibacterial properties by leveraging the inherent properties of quaternary ammonium chitosan. This reduces the VOC release of the polypropylene composition while simultaneously enhancing its antibacterial performance.

[0008] For example, in the antibacterial low-VOC polypropylene composition, the weight parts of the polypropylene resin can be any combination of 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, and 86 parts, and the weight parts of the toughening agent can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts. The weight parts of the filler can be any one or a combination of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 parts, and the weight parts of the functional additive can be any one or a combination of 0.5, 1, 2, 3, 4, and 5 parts.

[0009] For example, the mass ratio of chitosan quaternary ammonium salt, glycyl alanine and molecular sieve in the functional additive can be any one of 3:5:10, 6:10:10, 9:15:10, 12:20:10 or any combination of two of them.

[0010] Preferably, the mass ratio of the chitosan quaternary ammonium salt, glycyl alanine, and molecular sieve is (6~9):(10~15):10.

[0011] Preferably, the preparation method of the functional additive includes, but is not limited to, the following methods: Molecular sieve, glycyl alanine, and solvent are mixed and stirred, then filtered, washed, and dried to obtain glycyl alanine-modified molecular sieve; quaternary ammonium salt chitosan solution and glycyl alanine-modified molecular sieve are mixed and shaken, then filtered, washed, and dried to obtain the functional additive.

[0012] The stirring treatment is carried out at a temperature of 80~90℃ for 12~20h; the mass concentration of quaternary ammonium salt chitosan in the quaternary ammonium salt chitosan solution is 1~5g / L; and the shaking treatment is carried out for 20~28h.

[0013] Preferably, in the antibacterial low-VOC polypropylene composition, the polypropylene resin has a mass percentage content of not less than 54%.

[0014] In one embodiment, the functional additive has a mass percentage content of 0.4-5.0% in the antibacterial low-VOC polypropylene composition.

[0015] For example, in the antibacterial low-VOC polypropylene composition, the mass percentage of the functional additive may be any one or a combination of two of the following: 0.4%, 0.5%, 0.9%, 1%, 1.5%, 2%, 2.5%, 2.9%, 3%, 3.5%, 4%, 4.5%, 5.0%.

[0016] Preferably, the polypropylene resin includes at least one of homopolymer polypropylene and copolymer polypropylene.

[0017] Preferably, the melt flow rate of the polypropylene resin at 230°C and 2.16 kg load is 1~100 g / 10 min.

[0018] For example, the melt flow rate of the polypropylene resin at 230°C and 2.16 kg load can be any one or a combination of two of the following: 1 g / 10 min, 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 40 g / 10 min, 50 g / 10 min, 60 g / 10 min, 70 g / 10 min, 80 g / 10 min, 90 g / 10 min, and 100 g / 10 min.

[0019] More preferably, the melt flow rate of the polypropylene resin at 230°C and 2.16 kg load is 30~60 g / 10 min.

[0020] Preferably, the toughening agent comprises a polyolefin elastomer.

[0021] Preferably, the molecular sieve includes at least one of ZSM-5 molecular sieve, type A molecular sieve, and type Y molecular sieve.

[0022] Preferably, the molecular sieve has an average particle size of 0.6~4μm.

[0023] Preferably, the antibacterial low-VOC polypropylene composition further includes the following components in parts by weight: 65-75 parts of polypropylene resin, 10-15 parts of toughening agent, 15-20 parts of filler, and 1-3 parts of functional additive.

[0024] In this invention, the filler may include at least one of talc, kaolin, montmorillonite, glass fiber, mica, quartz, feldspar, bentonite, zeolite, and perlite.

[0025] Based on the needs of practical applications, those skilled in the art can appropriately introduce some common auxiliary components, such as antioxidants to improve the aging resistance of the composition, lubricants to improve the processing performance of the composition, and light stabilizers to improve the light stability of the composition, etc., provided that they do not adversely affect the performance of the polypropylene composition.

[0026] Preferably, the antibacterial low-VOC polypropylene composition further includes the following components in parts by weight: 0.1 to 1 part of additives, wherein the additives include at least one of antioxidants, lubricants, and light stabilizers.

[0027] In this invention, the antioxidant may be at least one of phosphite antioxidants and hindered phenolic antioxidants; the light stabilizer may be at least one of benzotriazole light stabilizers and hindered amine light stabilizers; and the lubricant may be at least one of vinyl bis-stearamide, magnesium stearate, zinc stearate, and polyethylene wax.

[0028] In a second aspect, the present invention provides a method for preparing the antibacterial low-VOC polypropylene composition as described in the first aspect, comprising the following steps: The components are mixed and then melt-extruded and granulated using a twin-screw extruder to obtain the antibacterial, low-VOC polypropylene composition.

[0029] Thirdly, the present invention provides the application of the antibacterial low-VOC polypropylene composition as described in the first aspect in the preparation of automotive interior parts.

[0030] Fourthly, the present invention provides an automotive interior component made of a polypropylene composition as described in the first aspect.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses a molecular sieve modified with chitosan quaternary ammonium salt and glycine alanine as a functional additive, and introduces the functional additive into the polypropylene composition. This can improve the antibacterial properties of the polypropylene composition, give the polypropylene composition low VOC release performance, and make the polypropylene composition suitable for the preparation of automotive interior parts. Detailed Implementation

[0032] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0033] Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this invention are all commonly used ordinary reagents and instruments.

[0034] The source information and performance parameters of the components described in each embodiment and comparative example are as follows: Polypropylene resin 1: The type is copolymer polypropylene, the grade is EP648U, the manufacturer is ExxonMobil, and the melt flow rate at 220℃ and 10Kg load is 60g / 10min according to ISO1133-2011. Polypropylene resin 2: The type is copolymer polypropylene, the grade is PP M50RH, the manufacturer is Zhenhai Refining & Chemical, and the melt flow rate at 220℃ and 10Kg load according to ISO1133-2011 is 50g / 10min. Polypropylene resin 3: The type is copolymer polypropylene, the grade is PP 7585E1, the manufacturer is ExxonMobil, and the melt flow rate at 220℃ and 10Kg load according to ISO1133-2011 is 49g / 10min. Polypropylene resin 4: The type is copolymer polypropylene, the grade is PP 8285E1, the manufacturer is ExxonMobil, and the melt flow rate at 220℃ and 10Kg load is 30g / 10min according to ISO1133-2011. Polypropylene resin 5: The type is homopolymer polypropylene, the grade is PP M60T, the manufacturer is Zhenhai Refining & Chemical, and the melt flow rate at 220℃ and 10Kg load according to ISO1133-2011 is 55g / 10min. Molecular sieve 1: ZSM-5 molecular sieve, manufactured by Jianlong Micro-Nano, with a measured average particle size of 4μm; Molecular sieve 2: Type A molecular sieve, manufactured by Jianlong Micro-Nano, with a measured average particle size of 0.6 mm; Molecular sieve 3: Y-type molecular sieve, manufactured by Jianlong Micro-Nano, with a measured average particle size of 1.2μm; Chitosan quaternary ammonium salt: brand name A2309, manufacturer is Shanghai Shifeng Biotechnology Co., Ltd.; Functional Additive 1: Its preparation method includes the following steps: (1) Add the dried molecular sieve 1 to toluene, stir evenly, heat to 85℃ and then add an aqueous solution of glycyl alanine (the mass percentage of glycyl alanine is 100 g / L), stir and reflux at 85℃ for 16 h, filter by vacuum and wash with toluene, and then dry to obtain glycyl alanine modified molecular sieve; (2) Dissolve quaternary ammonium salt chitosan in acetic acid solution, then add glycyl alanine modified molecular sieve, and stir at 130 r / min The mixture was shaken at 20℃ for 24 hours, then vacuum filtered and washed with deionized water, and finally vacuum dried to obtain functional additive 1. The mass ratio of molecular sieve 1 to toluene was 1 g: 100 mL, the mass ratio of quaternary ammonium salt chitosan to acetic acid solution was 3 g: 1 L, the volume percentage of acetic acid in the acetic acid solution was 6%, and the mass ratio of chitosan quaternary ammonium salt, glycine alanine and molecular sieve 1 was 6:10:10. The grade of chitosan quaternary ammonium salt was A2309, and the manufacturer was Shanghai Shifeng Biotechnology Co., Ltd. Functional Additive 2: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 2, the mass ratio of chitosan quaternary ammonium salt, glycine alanine and molecular sieve 1 is 9:15:10. Functional Additive 3: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 3, the mass ratio of chitosan quaternary ammonium salt, glycine alanine and molecular sieve 1 is 3:5:10. Functional Additive 4: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 4, the mass ratio of chitosan quaternary ammonium salt, glycine alanine and molecular sieve 1 is 12:20:10. Functional Additive 5: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 5, molecular sieve 1 is not used, but molecular sieve 2 is used to replace molecular sieve 1 in an equal amount. Functional Additive 6: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 6, molecular sieve 1 is not used, but molecular sieve 3 is used to replace molecular sieve 1 in an equal amount. Functional Additive 7: Glycyl alanine modified molecular sieve. Glycyl alanine modified molecular sieve was prepared according to step (1) in the preparation method of functional additive 1. The mass ratio of glycyl alanine to molecular sieve 1 was 10:10. Functional Additive 8: Its preparation method is as follows: Quaternary ammonium salt chitosan is dissolved in acetic acid solution, then molecular sieve 1 is added, and the mixture is shaken at 130 r / min and 20℃ for 24 h. After vacuum filtration and washing with deionized water, functional additive 8 is obtained by vacuum drying. The mass ratio of molecular sieve 1 to toluene is 1 g: 100 mL, the mass ratio of quaternary ammonium salt chitosan to acetic acid solution is 3 g: 1 L, the volume percentage of acetic acid in the acetic acid solution is 6%, and the mass ratio of chitosan quaternary ammonium salt to molecular sieve 1 is 6:10. The grade of chitosan quaternary ammonium salt is A2309, and the manufacturer is Shanghai Shifeng Biotechnology Co., Ltd. Functional Additive 9: Its preparation method differs from that of Functional Additive 1 in that, when preparing Functional Additive 9, quaternary ammonium salt chitosan is not used. Instead, chitosan with brand name C434547 and manufacturer Aladdin is used to replace quaternary ammonium salt chitosan in an equal amount. Toughening agent: Polyolefin elastomer, model POE 7447, manufactured by Dow Chemical. Filler: Talc powder, model TYT-777A, manufactured by Liaoning Beihai Industrial Group; Light stabilizer: 2,2,6,6-tetramethyl-4-piperidine stearate (UV-3808); Antioxidant: It is a compound of tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168) and pentaerythritol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010) in a 1:1 mass ratio.

[0035] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0036] Examples 1-13 Examples of the antibacterial low-VOC polypropylene composition of the present invention are shown in Table 1, and the components and their weight ratios of the antibacterial low-VOC polypropylene composition are shown in Table 1.

[0037] The method for preparing the antibacterial low-VOC polypropylene composition includes the following steps: The components are mixed and then melt-extruded and granulated using a twin-screw extruder to obtain the antibacterial low-VOC polypropylene composition. During melt extrusion, the temperature zones of the twin-screw extruder from the feeding section to the die head are as follows: zone 1 to 2 is 180~200℃, zone 3 to 5 is 200~220℃, zone 6 to 10 is 200~220℃, the screw speed is 200rpm, and the screw length-to-diameter ratio is 40:1.

[0038] Table 1 (Unit: parts by weight) Comparative Examples 1-7 The only difference between each comparative example and the embodiment is the type and ratio of components, as shown in Table 2.

[0039] Table 2 (Unit: parts by weight) To verify the performance of the polypropylene compositions described in this invention, the polypropylene compositions prepared in each embodiment and comparative example were subjected to the following performance tests, with the specific steps as follows: (1) Antibacterial rate: The sample was injection molded into a 50mm*50mm*3mm strip, and the strain used for testing was Escherichia coli according to the test method of GB / T 31402-2023. The antibacterial rate was measured after 24 hours.

[0040] (2) VOC emission performance: tested in accordance with ISO 12219-2:2012.

[0041] The test results are shown in Tables 3 and 4.

[0042] Table 3 Table 4 As can be seen from Examples 1-13, the present invention uses molecular sieves modified with chitosan quaternary ammonium salt and glycine alanine as functional additives, which can improve the antibacterial properties of polypropylene compositions and give polypropylene compositions low VOC release performance, VOC content ≤62ug(C) / g, and antibacterial rate ≥90.5%, so that polypropylene compositions can meet the application requirements of automotive interior parts.

[0043] Compared with Example 1, the functional additive used in Comparative Example 1 does not contain quaternary ammonium salt chitosan, which significantly increases the VOC release of the polypropylene composition. Meanwhile, the antibacterial effect of glycyl alanine is very small, which significantly reduces the antibacterial performance of the polypropylene composition to as low as 3.5%.

[0044] Compared with Example 1, the functional additive used in Comparative Example 2 does not contain glycyl alanine, which significantly increases the VOC release of the polypropylene composite composition and significantly reduces its antibacterial properties.

[0045] Compared with Example 1, Comparative Example 3 used functional additives that did not contain quaternary ammonium chitosan, but instead used ordinary chitosan to replace quaternary ammonium chitosan, which significantly reduced the antibacterial properties of the polypropylene composition.

[0046] Compared with Example 1, Comparative Examples 4-6 did not use the functional additives described in this invention. Comparative Example 4 introduced a single molecular sieve, which has poor dispersibility in the composition and is difficult to function, resulting in a significant increase in VOC release of the polypropylene composite composition and almost no antibacterial properties. Comparative Example 5 introduced a single quaternary ammonium salt chitosan, which significantly increased the VOC release of the polypropylene composite composition. Comparative Example 6 introduced a single glycyl alanine, which has no molecular sieve fixation effect. Glycyl alanine is volatile, increasing the VOC release of the polypropylene composite composition and almost no antibacterial properties.

[0047] As can be seen from Example 1 and Comparative Example 7, the present invention can improve the antibacterial properties of polypropylene compositions by introducing appropriate amounts of functional additives into the polypropylene compositions, while also giving the polypropylene compositions low VOC release properties.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An antibacterial low VOC polypropylene composition characterized in that, It includes the following components in parts by weight: 59-86 parts of polypropylene resin, 5-20 parts of toughening agent, 10-25 parts of filler, and 0.5-5 parts of functional additives; The functional additive includes glycyl alanine-modified molecular sieve, which is coated with chitosan quaternary ammonium salt. The mass ratio of chitosan quaternary ammonium salt, glycyl alanine and molecular sieve in the functional additive is (3~12):(5~20):

10.

2. The antibacterial low VOC polypropylene composition according to claim 1, wherein The mass ratio of chitosan quaternary ammonium salt, glycine alanine, and molecular sieve is (6~9):(10~15):

10.

3. The antimicrobial low VOC polypropylene composition of claim 1, wherein, The polypropylene resin includes at least one of homopolymer polypropylene and copolymer polypropylene.

4. The antimicrobial low VOC polypropylene composition of claim 1, wherein, The melt flow rate of the polypropylene resin at 230°C and 2.16 kg load is 1~100 g / 10 min.

5. The antimicrobial low VOC polypropylene composition of claim 1, wherein, The toughening agent includes a polyolefin elastomer.

6. The antimicrobial low VOC polypropylene composition of claim 1, wherein, The molecular sieve includes at least one of ZSM-5 molecular sieve, type A molecular sieve, and type Y molecular sieve.

7. The antimicrobial low VOC polypropylene composition of claim 1, wherein, It also includes the following components in parts by weight: 0.1 to 1 part of additives, wherein the additives include at least one of antioxidants, lubricants, and light stabilizers.

8. A method for preparing an antibacterial low-VOC polypropylene composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: The components are mixed and then melt-extruded and granulated using a twin-screw extruder to obtain the antibacterial, low-VOC polypropylene composition.

9. The use of an antibacterial, low-VOC polypropylene composition as described in any one of claims 1 to 7 in the preparation of automotive interior parts.

10. An automotive interior component, characterized in that, Made from the polypropylene composition as described in any one of claims 1 to 7.

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